Piston ring and method of forming the same



Nov. 2, 1943. v. F. ZAHODIAKIN 2,333,457

PISTON RING AND METHOD OF FORMING THE SAME Filed Oct. 17, 1940 IN VENTOR.

BY MWATTORNEYSj Patented Nov. 2, 1943 UNITED STATES PATENT OFFICE PISTONRING AND METHOD OF FORMING THE SAME 3 Claims.

This invention relates to improvements in oil rings of the type adaptedto be used in pistons. The improved ring of this invention is ofparticular value for use as an oil ring for the pistons of internalcombustion engines but is not limited to this use. It is capable of use,with the same advantages, as the oil ring for the pistons of pumps,steam engines or any installation where it is necessary to prevent theescape of oil along a cyilnder wall past a. piston.

It has been one of the objects of the present inventor to provide an oilring for pistons which is adapted to the above uses and which willreadily and easily conform to any irregularity in the contour of acylinder and will, in this respect, be of greatvalue for use in worncylinders. In other words the general purpose has been to provide an oilflow control ring which will conform to localized irregularities ordistortions as well as to general irregularities in the contour of thecylinder wall.

It has been a further object of the present inventor to provide a pistonring which can be made, preferably, from a single strip of metal in anextremely simple manner by corrugating the strip and, thereafter,swaging the crowns of the corrugations adjacent the outer periphery ofthe ring. More specifically the object has been to provide a ring formedof a corrugated strip in which the various corrugations have a portionof their crowns at the outer ends spread out so as to be disposed inclose minute proximity including relatively sharp comers presentingopenings insufflcient in size to permit the passage of oil. Referencemay be had to the patent to Victor F. Zahodiakin, No. 1,957,927disclosing and claiming a ring formed of overlapping corrugations.

The present ring has the further advantage I that the top and bottomwalls of the crown porbeen to provide a method of forming this improvedring from the single strip of metal through the simple operations ofcorrugating and swaging. More specifically the crowns of the variouscorrugations are swaged to provide for maximum sealing efllciency wherethe piston ring engages the cylinder wall. Other advantages or theinvention will be more fully apparent from the description of thedrawing in which:

Figure 1 is a fragmentary top plan view or the improved ring.

Figure 2 is a perspective view showing in detail the manner in which thering is made and showing the shape of the finished corrugations.

Figure 3 is a top plan view of a portion of a ring showing it inenlarged detail with one corrugation broken away to show its interior.

As shown in the drawing the ring is formed from a strip of metal I. Thestrip is corrugated as shown at the left-hand side of Fig. 2 to providea series of corrugations ll, having rounded crowns l2. The corrugationsthus formed are swaged by means of forming tools to flatten and spreadout the crowns at the outer periphery of the ring.

The intermediate portions of the vertical walls of the corrugations maybe held by means of inserted dies while other dies are inserted into therounded portions of the crowns to spread and flatten the corrugations asshown in Fig. 2. The swaging takes place inwardly a short distance. As aresult the crowns are flat providing flat top or bottom walls I3 andvertical flat walls H.

The adjacent fiat side walls of the adjacent corp rugations are minutelyspaced and formed so as to be disposed on radial lines when the strip isbent to circular form.

The ring is flexible and the vertical walls l5 beneath the flattenedcrown portions adequately brace the top and bottom walls of the ring.Since the structure is integral and there are no overhanging parts thereis very little opportunity for breaking or fracturing of the ringstructure. Ample oil clearance passage-way is provided in the interiorof the ring and a great deal of ring engaging area is afforded as in thering disclosed in the patent to Zahodiakin, above mentioned.

Having described my invention, I claim:

1. A piston ring comprising, a single strip of metal includingcontinuous corrugations, the side walls of each of said corrugationsbeing spaced circumferentially, thecrowns or said corrugations adjacentthe outer periphery of the ring being flat and the remaining portions ofthe crowns being rounded, the fiat portions of the corrugationsextending circumferentially substantially into engagement with butminute clearances therebetween and portions of the side walls of thecorrugations being vertical.

2. A piston ring, comprising, a strip of resilient sheet metal andconsisting of a series of open corrugations. the crowns of saidcorrugations being round with the exception of those portions adjacentthe outer periphery of the ring, said latter portions being flat so asto present substantially continuous top and bottom walls.

3. A piston ring comprising, a strip of resilient sheet metal andconsisting of a series 01' corrugations, said corrugations adjacent theouter periphery of the ring having flat flared crowns presentingstraight circumferential walls and straight side wall portions, saidside wall portions being adJacently disposed and minutely spaced, saidside walls flaring inwardly from said straight side wall portions andcontinuing straight side wall portions extending from these flaredportions.

VICTOR. F. ZAHODIAKIN.

